app.py

import gradio as gr

def handle_chat(message, history):
    if history is None:
        history = []
    history.append({"role": "user", "content": message})
    history.append({"role": "assistant", "content": f"You said: {message}"})
    return history, history

with gr.Blocks() as demo:
    chatbot = gr.Chatbot(type="messages")
    state = gr.State([])

    with gr.Row():
        msg = gr.Textbox(placeholder="Type a message...")
        submit = gr.Button("Send")

    submit.click(handle_chat, [msg, state], [chatbot, state])
    msg.submit(handle_chat, [msg, state], [chatbot, state])

demo.launch()